Mammary malignant peripheral nerve sheath tumor in a 93-year-old male: case report.

Breast sarcomas are rare malignancies, accounting for <1% of all breast malignancies and <5% of all soft tissue sarcomas. Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that arise from peripheral nerves. Their occurrence in the breast is exceedingly rare. This is the fourth published case of mammary MPNST in a male patient. We present a case of a 93-year-old male with a three-year history of a progressively enlarging and painful right breast mass. Examination revealed a 20 × 30 cm immobile, fungating, and ulcerating mass with purulent discharge. Histopathological assessment confirmed a high-grade spindle cell sarcoma, and immunohistochemistry revealed positivity for vimentin, S100 protein, and p63 in a focal pattern, confirming the diagnosis of MPNST. The patient underwent a right mastectomy, achieving a surgical clearance. After 3 months, he passed away with malignant pleural effusion due to lung metastasis.